Seyede Fateme Bagheri - Department of Chemistry, Faculty of Sciences, University of Guilan, Rasht, Iran
Naz Chaibakhsh - Department of Chemistry, Faculty of Sciences, University of Guilan, Rasht, Iran

Azo dyes are organic compounds which contain the coloring azo function (N=N-). Although these dyesare widely used in the industry but they are harmful to the environment. In recent years, development ofnew approaches, technologies or designs with the objective to solve environmental problems or to improveexisting systems in this field have increased. One of these development can be found in the advancedoxidation processes (AOP) with application of different technologies. Among them photocatalyticozonation process is an interesting method. In this study, Acid Blue 113, commonly used as a textile dye,was photocatalytically degraded using hematite nanaoparticles under irradiation of visible light (VL).Response surface methodology (RSM) based on central composite rotatable design (CCRD) wasemployed to study and optimize the treatment process. The effects of several parameters such as pH, theamount of hematite and reaction time were also examined. At the optimal conditions of pH=7, 47.87 mg ofthe nanocatalyst, 9 min and 0.60 g/L.h of ozone,100% of the dye was removed. The proposed method canefficiently degrade the recalcitrant dye and can be applied to the treatment of wastewaters containingsynthetic dyes.

Photocatalysis, Dye degradation, Hematite, Ozonation, Optimization, Acid Blue 113